This invention relates to liquid spray guns which utilize a reciprocation-type piston pump, and more specifically, to a system for usefully disposing of leakage flow from said pump.
Liquid spray guns which are used to spray liquids such as paint are known in the art. Some of the pumps include an electromagnetic motor which includes an armature that oscillates with the AC cycle. The oscillating armature drives a piston pump, and more specifically a piston rod, which reciprocates and draws the liquid to be sprayed from a reservoir, such as a paint can, and delivers the liquid to a spray nozzle. Such guns are shown in U.S. Pat. Nos. 3,445,068; 3,899,134; and 4,160,525.
In such guns liquid or paint leaks past the piston rod during use. The leakage liquid is collected and exits the pump through a collection or blow-by port. The exiting liquid is then collected for disposal or reuse. If the gun uses a suction tube for drawing liquid from a reservoir, such as a paint can, a long tube is provided to return the leakage liquid to the reservoir. If a liquid supply cup is being used, then the leakage liquid or paint is returned to the supply cup, but this requires regular emptying of the cup.
It is an object of this invention to more efficiently recycle the leakage liquid.
It is another object of this invention to eliminate the long return tube and the emptying of the supply cup.
These and other objects of this invention will become apparent from the following description and appended claims.